Patent GB-758203-A (GB)
Title: Lubricant composition
IPC: C10M145/16
Filed: 1953-11-26
Abstract: An oil-soluble copolymer of molecular weight at least 20,000 comprises (A) an ethylenic compound having a group of from 4 to 30 aliphatic carbon atoms and (B) an a ,b -unsaturated carboxylic acid, the copolymer comprising 1 to 20 monomer units (A) for each monomer unit (B) and containing at least one free carboxyl group per molecule.  Acids specified are monocarboxylic acids, e.g. acrylic and methacrylic acids and polycarboxylic acids, e.g. maleic and fumaric acids, and partial esters, amides or amine salts thereof, e.g. monododecyl and mono-2-ethylhexyl maleates.  A list is given.  (A) may be an olefin, ether, ester, ketone, aldehyde or diene (e.g. 2-hexadecylbutadiene-1,3) and lists are given.  Preferably (A) is a C3 to C30 alkyl ester of an unsaturated mono- or dicarboxylic acid. Oil-solubilizing radicals may also be introduced by esterification of copolymers containing acidic or alcoholic groups.  The copolymers may be prepared in bulk, emulsion or in solution, e.g. in benzene, toluene, xylene or petroleum, or a polymer of a monomer (A), e.g. dodecyl methacrylate, may be partially saponified.  Polymerization catalysts described are benzoyl, acetyl, dibenzoyl, di-t.-butyl and di-t.-amyl peroxides; t.-butyl hydroperoxide; azodicyclohexane carbonitrile and azodiisobutyronitrile.  The catalyst, solvent or monomer may be added incrementally.  The copolymers may be added to a wide variety of natural or synthetic lubricating oils to impart detergent and anti-wear properties.  Examples are given of terpolymers and polymers comprising more than three different monomeric units.  In Example 7 polymerization is terminated after 4 hours.  Specifications 668,539, 686,381 and 686,384 are referred to.ALSO:A lubricating composition comprises a major proportion of an oil of lubricating viscosity and from 0.1 to 10 per cent of a copolymer of molecular weight at least 20,000 and comprising monomer units of (A) an ethylenic compound having a group of from 4 to 30 aliphatic carbon atoms and (B) an a, b -unsaturated carboxylic acid, the copolymer comprising 1 to 20 monomer units of (A) for each monomer unit of (B) and containing at least one free carboxyl group per molecule (see Group IV(a)).  Lubricating oils mentioned include mineral oils and synthetic oils such as alkylated hydrocarbons (e.g. alkylated waxes), hydrogenated hydrocarbon polymers, condensation products of chlorinated alkyl hydrocarbons with aryl compounds and polymers of propylene and/or ethylene oxide and esters or ethers thereof (e.g. the acetate of polymerized propylene oxide).  Other oils which may be used are di(2-ethyl-hexyl) sebacate, tricresyl phosphate and silicate esters.  The composition may also contain pour point depressants, oiliness and extreme pressure agents, antioxidants, corrosion inhibitors, blooming agents, thickening agents, viscosity improvers and auxiliary detergents or anti-wear agents.  The efficacy as detergents and anti-wear properties of the copolymers are illustrated in examples 10-16 wherein the results of testing various copolymer/mineral oil compositions are set out. Specifications 668,539, 686,381 and 686,384 are referred to.